How does the addition of an extra methyl group in methylallosamidin affect inhibition?

Methylallosamidin is an allosamidin derivative with an extra methyl group added to the O6 hydroxyl on the -3 allosamine. Its apparent IC50 value against human chitinase is 2.6 nM.

Adding an extra methyl group to the O6 hydroxyl on the -3 allosamine in methylallosamidin results in a similar increase in inhibition compared to allosamidin. Like other derivatives, its structural interactions with the enzyme explain these effects in terms of altered hydrogen bonding and hydrophobic interactions.